Film illumination system

ABSTRACT

An illuminator film system may include one or more pre-cut sections of optical film applied to a waveguide to allow light to exit the waveguide through the film in a predetermined manner. The one or more pre-cut sections may be removed and reapplied during a procedure to redirect the light. A laminated illuminator film may be provided that uses a laminated optical film structure to direct light from a fiber optic input. Such a laminated illuminator film may be very low profile, low cost and easy to apply to a retractor for providing illumination during a surgical procedure.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/818,090 filed Jun. 12, 2007, now U.S. Pat. No. 7,686,492, whichclaims priority to U.S. Provisional Application 60/813,391, filed Jun.13, 2006.

FIELD OF THE INVENTIONS

The inventions described below relate to the field of medicine and morespecifically, to providing body cavity illumination for use in medical,dental and veterinary procedures.

BACKGROUND OF THE INVENTIONS

Existing technology for illumination during surgical/medical proceduresis often limited to overhead illumination. This illumination comes fromeither overhead lighting or head mounted fiber optic systems.Traditional overhead lighting systems face numerous limitations. Directexposure of the field from the overhead source is required. Changes inpatient or surgeon positioning requires repositioning of the lightsource. Frequent adjustments provide an inconvenience for the surgeonand disrupt the surgical flow. For deeper cavities, overhead systemsprovide poor quality illumination. Positioning of the surgeon, or theinstruments may shield the overhead lighting and prevent illuminationfrom reaching the field of the procedure.

Head mounted fiber optic systems are used frequently for more limitedsurgical exposures, however, these devices also have numerous drawbacks.First, the surgeon is tethered by the light cord attached to theheadset, limiting mobility in the operating room. Second, the devicesare associated with head and neck fatigue with frequent or moreprolonged use. Third, the devices require the surgeon to maintain asteady head and neck position to provide a constant and steadyillumination of the field. Fourth, the use of remote light sources andfiber bundles introduces tremendous inefficiencies into the system. Asix-foot fiber optic cable may lose 65% of the incoming light from alight source. The headlamp optical components may lose another 60% ofthe light from the fiber optic cable. In addition, surgeons using headmounted systems frequently complain of the heat generated by suchsystems.

In addition, both headlamp and overhead systems provide inadequateillumination when used with less invasive surgical procedures with alimited incision to access a deeper or broader surgical cavity. Forthese cases, both overhead and headlamp systems only illuminate afraction of the volume of the surgical space.

The introduction of minimally invasive surgical techniques, has raisedthe demand for delivery of high intensity light through minimal surgicalincisions into deep surgical fields. To address this demand, lightdelivery devices have been developed for delivery of light from remote,high intensity light sources to the surgical field. These devicesgenerally consist of bundles of optical fibers that are integrated withor directly adhere to surgical retractors to illuminate the field andare connected via fiber optic cable to a high intensity light source.While these devices provide a way to illuminate the surgical field, theyprovide highly inefficient illumination. The small bundle diameter issusceptible to being completely blocked by any surgical debris orsplatter such as blood or tissue, thereby requiring constant cleaning tomaintain illumination. In addition, due to the limited divergence angleand highly Gaussian intensity profile, these devices only provide asmall spot of light that requires constant repositioning to view theentire surgical area. In addition, these fiber optic light pipes arevery expensive to manufacture, requiring significant amounts ofexpensive human labor.

Waveguide illuminators are known in the art and typically allow light toexit the illuminator by using optical structures molded into the surfaceof the waveguide itself. Light injected into such waveguides istypically contained in the waveguide through total internal reflection.When the light strikes the optical structures, the reflection angle isinterrupted such that the light now refracts out of the waveguide. Suchsystems may be useful for illumination of deep tissues, but oftenrequire the use of expensive, specialized tooling or manufacturingprocesses. Moreover, these waveguides are rigid and must be designed tofit particular instruments so different waveguides must be available toaccommodate the variety of surgical instruments used in a given surgicalprocedure.

Still other applications may involve woven fiber optic strands or fiberoptic strands cut at various lengths to generate diffuse lighting. Lightescapes the fiber either through a nick in the surface of the fiber orbecause a material has been applied to the surface of the fiber thatdisrupts total internal reflection, or the light merely escapes out ofthe cut ends of the fiber. This type of diffuse illumination istypically not suitable for illumination of deep tissues because itprovides an insufficient level of illumination for tissues of interestand often shines light back into the surgeon's eyes, making viewing ofthe tissues difficult. Such systems are also expensive to manufacture.

SUMMARY

Light in medical applications may be used for illumination, diagnosticor therapeutic purposes. While this disclosure discusses primarilyillumination applications, diagnostic and therapeutic applications areunderstood to be included as well.

A film illumination system may include one or more pre-cut sections ofoptical film applied to a waveguide to allow light to exit the waveguidethrough the film in a predetermined manner. The one or more pre-cutsections may be removed and reapplied during a procedure to redirect thelight. A laminated illuminator film may be provided that uses alaminated optical film structure to direct light from a fiber opticinput. Such a laminated illuminator film may be very low profile, lowcost and easy to apply to a retractor for providing illumination duringa surgical procedure.

In an illumination technique according to the present disclosure, asmall, pre-shaped section of film is applied to the surface of awaveguide to allow light to exit the waveguide in a predetermined mannersubstantially only from the area to which the pre-shaped section of filmis applied. Said pre-shaped section of film becomes a simple, stick-onilluminator film when applied to the waveguide or light guide. Thispre-shaped section of film should have an area that is significantlysmaller than the surface area of the waveguide or light guide on towhich the pre-shaped or pre-cut section as been placed.

A film illumination system according to the present disclosure maycomprise one or more pre-cut sections of optical film, the pre-cut filmsections including optical structures, for example, prismaticstructures, for directing or focusing or diffusing light entering oneside of the film as it exits the opposite side of the film. Said pre-cutsection may also include one or more tabs for handling the pre-cutsection and for removeably placing the pre-cut section on to a plasticwaveguide. Pre-cut optical film sections may also include an adhesivelayer for adhering to the waveguide. The composition of the adhesivelayer may be selected to provide a refractive index specificallydesigned to enhance the leakage of light from the waveguide especiallyif the indices of the optical film layer and the waveguide are similar.

Tabs may be color coded for the type of light directing function such asfor example, diffuse, direction, focused, etc. The tab may also be usedto show the directionality of a directional film. The waveguide mayreceive light from any suitable light source and may control and containthe light inside of the waveguide through total internal reflection. Thewaveguide may have polished surfaces and/or coated surfaces to promoteinternal reflection.

A user may apply a pre-cut section or stick-on illuminator film to thewaveguide to allow light to exit the waveguide. The stick-on illuminatorfilm may also be removed and reapplied to a different part of thewaveguide and/or in a different orientation to direct light as desired.Multiple pre-cut sections may be applied to the same waveguide to createa desired illumination area.

For example, the waveguide or light guide may be a retractor made from asuitable light guiding material (e.g., acrylic, polycarbonate, silicone,glass, etc., that may be transparent or translucent) with a widthgreater than its thickness and a front surface that faces the surgicalarea. The light guide or waveguide may be a surgical instrument or maybe attached to a surgical instrument. Two generally diffusing pre-cutsections may be placed near the lateral edges of the retractor up adesired distance from its tip to provide generally diffuse illuminationof the surgical area, and a third pre-cut section may be placed betweenthe first two pre-cut sections, said third pre-cut section providing adirectional beam of light to illuminate a particular portion of thesurgical area. The surgeon may perform some work, then move or rotatethe directional pre-cut section to better illuminate another portion ofthe surgical area while keeping the other two diffuse precut sections inplace. At the end of the procedure, the pre-cut sections may be removedfrom the plastic waveguide and discarded while the waveguide may besterilized and reused. Damaged or occluded film sections may simply beremoved and replaced. The user may employ any combination of stick-onilluminator films to achieve desired illumination. Pre-cut sections of astick-on illuminator film may be provided at extremely low cost.

Alternatively, a laminated film illumination assembly may be formed froman optical fiber having a suitable connector end for attaching to lightsource or light guide cable and a free end that is laminated with atleast two layers of optical film. The optical fiber may be supplied as amono-fiber or as a bundle of optical fibers. In a preferred orientation,the optical fibers are placed at one of the narrow ends of a rectangularshaped laminate structure with enough of the free optical fibers held inthe laminate structure to hold the fibers securely and reduce thelikelihood that the fibers can be pulled out during normal use.Preferably, the bottom layer of the laminate structure has an insidesurface that is reflective or that has optical structures that serve toreflect light toward the top layer. The bottom layer also has a suitableadhesive on the outside surface for attaching the assembly to a surgicalinstrument, for example, a retractor. The upper layer preferablyincorporates optical structures that serve to diffuse, shape, focusand/or direct light coming into that layer. The space between the upperand lower films is preferably occupied by an air layer, but anintermediate light guide layer, e.g., a suitably thick acrylic film or athin molded polycarbonate or silicone piece, may occupy this space topromote total internal reflection or the two films may be adheredtogether thereby eliminating any substantial air space wherein anadhesive may promote internal reflection. The laminated film section maybe made to be more or less flexible by employing such materials, or thefilm may be treated or structured to promote or restrict flexibility.Another protective transparent film may be placed on the upper film toprotect the optical structures. Light exits the free optical fibers atone end of the laminate structure, travels along the laminate structureand is eventually reflected off of the lower layer and through the upperlayer where it is directed as desired to illuminate tissue for surgical,diagnostic or therapeutic purposes. The user merely attaches a lightsource, e.g., a fiber optic light guide cable connected to a xenon,halogen or LED light source, to the connector end, peels a release linerfrom the adhesive on the bottom layer and attaches the assembly to asurgical instrument, e.g., a metal retractor. At the end of theprocedure, the user may discard the assembly because of its low cost. Alaminated illuminator film may be made very thin due to the thinness ofthe optical fibers and films of which it is made. A thin illuminator maybe attached to a retractor and not take up valuable space needed toperform the surgery. It may be made in different sizes, thereby makingthe illuminator suitable for many types of surgical instruments and manytypes of surgeries. For example, a flat rectangular shape may besuitable for flat instruments such as a retractor blade. Alternatively,the flat film laminate may be formed as a cylinder, e.g., by attachingthe two ends of the rectangular shaped film laminate, to slip over around instrument such as nerve root retractor. Other instrumentgeometries may be accommodated by suitably shaping the film laminate.Furthermore, because the material is very inexpensive and the assemblyprocess can be substantially automated, a laminated illuminator film maybe very inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a surgical illumination system employinga pre-cut optical illuminator film.

FIG. 2 is a perspective view of an alternate illuminator using pre-cut,stick-on film.

FIG. 3 is a close up view of pre-cut illuminator films with directionalbeams.

FIG. 4 is a close up view of pre-cut illuminator film with a combinationdiffuse and directional beam.

FIG. 5 is a cross-section of an optical fiber termination formed fromoptical films.

FIG. 5 a is a cross-section of an alternative optical fiber terminationformed from optical films.

FIG. 6 is a cross-section of an optical fiber termination formed fromoptical films with an air gap.

FIG. 6 a is a cross-section of an alternative optical fiber terminationformed from optical films with an air gap.

FIG. 7 is a cross-section of an optical fiber termination formed fromoptical films with a light guide section.

FIG. 8 is a perspective view of an illuminator assembly using a fiberoptic ribbon cable and optical films.

FIG. 9 is a perspective view of an optical film illumination assembly ona surgical retractor.

DETAILED DESCRIPTION OF THE INVENTIONS

Surgical illumination system 10 of FIG. 1 includes surgical retractor 12with handle 12H, waveguide 14 and fiber optic light guide cable 16,which is attached to any suitable light source. Waveguide 14 functionsto receive and conduct light from light guide cable 16 and the waveguidecontains the light through total internal reflection. Without anysurface interruptions, light energy contained in the waveguide wouldstay contained in the waveguide, subject to minor absorption, refractionand other losses as they occur over time. Stick-on illuminator film 17is made from an optical film that changes the refractive index of thearea of waveguide 14 to which the film is attached. Stick-on illuminatorfilm 17 is provided with tab 18 to facilitate handling of theilluminator film. When stick-on illuminator film 17 is attached towaveguide 14, directional light 20 is allowed to escape and illuminate asurgical area of interest.

Waveguide 14 may be connected to an external light source, such as axenon light source through fiber optic light guide cable 16, or it mayhave an integrated light source, such as an integrated LED includingdrive electronics and battery. Alternatively, waveguide 14 may beattached to a portable light source, such as a portable LED lightsource.

The shape of stick-on illuminator 17 may be any suitable shape and theshape geometry may be determined, at least in part, by the desiredillumination target. For example, a circular precut section may be moresuitable for a round illumination target and a rectangular precutsection may be suitable for a wide angle illumination target. Suchsuitable illumination target geometries may be combined to create acombined illumination target. For example, a precut section may includea rectangular portion for providing a percentage of the available lightfor wide angle illumination and a circular portion for providing apercentage of the available light for spot illumination.

In an alternative configuration, waveguide retractor 22 of FIG. 2 servesas the mechanical retractor and the light waveguide and is attached toany suitable light source through fiber optic light guide cable 23. Inthis configuration, stick-on illuminator film 24 is not provided with atab, and it also provides diffuse illumination 26 that may be suitablefor illuminating a larger surgical area than stick-on illuminator film17 of FIG. 1. In this instance, illumination 26 may be hemispherical,but it may be preferred to reduce the amount of light be reflected backup into a surgeon's eyes. Waveguide retractor 22 may be a rigid deviceformed of any suitable material, e.g., molded polycarbonate or acrylic,or may be a flexible device, e.g., molded silicone. Waveguide retractor22 may be in any suitable shape, e.g., bar, tube, etc. and includeshandle 22H.

FIG. 3 provides a close-up view of surgical illuminator 28 showingdistal end 29 of waveguide 30. Directional stick-on illuminator films 32and 34 are shown with respective tabs 33 and 35 that also mark thedirection of the respective directed light output 32L and 34L, i.e., thelight output is in the direction opposite of the tabs. Tab 33 ofstick-on illuminator film 32 is pointed to the right, indicating thatthe direction of illumination output 32L is to the left to illuminatearea of interest 36 that is to the left of waveguide 30. Tab 35 ofstick-on illuminator film 34 is pointed to the left, indicating that thedirection of illumination output 34L is to the right to illuminate aparticular area of interest 37 that is to the right of waveguide 30.

Referring now to FIG. 4, combination pre-cut illuminator film 38incorporates diffuse and focused illumination features. Pre-cut,stick-on film element 38 is attached to a light conducting waveguidesuch as waveguide 40. Stick-on film element 38 has a diffuse lightoutput portion 42 that creates diffuse light 43 to illuminate a generalsurgical area and has a directed light output portion 44 that createsdirected light 45 that illuminates a specific surgical area such as area46. Pre-cut, stick-on film element 38 is fabricated using standard filmconverting techniques. Again, the user positions the waveguide, thenapplies the stick-on illuminator film, or the illuminator film may bepre-applied to the waveguide before positioning the waveguide into thesurgical field. The diffuse output portion may be designed to provideany pattern of diffuse light, e.g., lambertian, planar, curved, etc. Thedirected output portion may be designed to provide any pattern ofdirected light, e.g., circular, polygonal, etc. The diffuse outputportion may even be constructed using two or more directional opticalfilms providing two or more directional illumination outputs, e.g., acircular spot of light to the right of the waveguide midline and asquare spot of light to the left of the waveguide midline.

Optical termination 48 of FIG. 5 is formed of laminated optical filmelements such as film elements 49 and 50 at the end of any suitablelight guide such as fiber optic cable 52. Optical film 49 is illustratedas the lower portion with adhesive layer 53 and preferably serves areflective function sending light to the upper portion. Optical film 50is the transmissive upper portion with adhesive layer 55 and may operatein a focused light directing function or a light diffusing mode or both.In this configuration, adhesive layers 53 and 55 are thick enough andhave sufficient optical clarity to allow light from fiber 52, which maybe a fiber bundle or a fiber ribbon cable or other suitable arrangementof fibers, to propagate at least partially along the adhesive layers sothat light exits substantially along output surface 54 of optical film50 that extends beyond fiber 52.

If the adhesive layers are not so configured, then the film layers maybe shortened as shown in FIG. 5A, showing alternative cable illuminator58 which includes light cable 60, upper light directing film 62 andlower light reflecting film 64. Light exiting light cable 60 encounterslower reflecting film 64, causing the light to be directed toward upperlight directing film 62, which may be configured to deliver diffuselight such as light 65, directed light such as light 66 or somecombination thereof. Depending on the thickness of upper light directingfilm 62, the distribution of the light angles from light cable 60 andthe paths that light rays take within the film laminate, some light mayshine out the end of illuminator 58 and may actually shine downwarddirection past lower light reflecting film 64.

In an alternative configuration, lower light reflecting film 64 may bereplaced with another piece of upper light directing film 62 to convertthe highly Gaussian distributed light from light cable 60 to a morediffuse distribution that may be more useful in a diagnostic ortherapeutic application or in an application where light shining in morethan one direction is desired.

Referring now to FIG. 6, laminated optical termination 68 is configuredto engage any suitable light input structure such as an optical fiberbundle or a single core optical fiber or a length of polycarbonate,acrylic, silicone or other suitable light-conducting material such aslight conduit or cable 70. Light reflecting film 71 directs light fromlight cable 70 above to light output film 72, which may provide diffuseillumination, directional illumination or a combination thereof. In thisconfiguration, an air chamber such as air chamber 73 is created to allowall the light from light cable 70 above to be directed down the lengthof the optical film laminate structure created by joining films 71 aboveand 72 above along their edges. Films 71 above and 72 above arepreferably cut in a rectangular shape, but may also be cut in any othersuitable shape.

As shown in FIG. 6A, air chamber 74 of laminated optical termination 76may be supported by a frame such as frame 77 made of a suitablematerial, e.g., plastic or metal, to help keep the air chamber openduring use. Directing film 78 and reflecting film 79 perform the samefunction as the respective films in FIG. 6. Frame 77 may have areflective surface at end 77E opposite of the light input from inputcable 80 or may have a layer of reflective film 81 to help ensure thatlight only exits directing film 78.

Referring now to FIG. 7, laminated film terminator 82 is sized to engagelight input cable 84, which is preferably a fiber optic ribbon with thefibers generally planar in a side by side orientation. The ends of thefibers, ends 86, contact waveguide 88, which propagates light along thelength 82L of the laminate structure. Reflecting film 89 serves todirect light toward output film 87. Termination waveguide 88 may befabricated from any suitable optical material such as polycarbonate,acrylic or silicone or another layer of optical film. In thisconfiguration, the thickness of termination waveguide 88 is at least thesame thickness as light input cable 84 to help ensure that all lightfrom light input cable 84 enters termination waveguide 88. Terminationwaveguide 88 may also incorporate optical structures, e.g., that aremolded in or created via a hot stamp process that may help direct thelight from light input cable 84 out to a surgical area to beilluminated.

Alternatively, a laminated film termination such as termination 90 ofFIG. 8 engages a suitable light input element, for example, a fiberoptic ribbon cable such as ribbon cable 92. Output or top film 93 andreflective or bottom film 94 are adhered together along terminator edges90E. In this configuration, fiber optic ribbon cable 92 may have fibersextending the entire length of the laminated termination. In this case,the light may escape individual fibers where each fiber contacts topfilm 93 and/or bottom film 94, or the fibers may be nicked or otherwisetreated to allow light to escape the fibers directly without the need tocontact either the top film or the bottom film. Fiber optic ribbon cable92 may be a bundle of fibers whose cut ends are arranged in a particularshape, e.g., the bundle may be round at the input connector and may berectangular or some other shape at the film laminate end, it may be aribbon cable where fibers are typically arranged side to side, or it maybe a single core fiber.

Laminated illuminator system 96 of FIG. 9 includes laminated filmtermination 97 on light input cable 98 attached to a retractor such asretractor 99 having handle 99H. Input connector 100 serves to connectthe illuminator system to a source of light. Light input cable 98conducts light from connector 100 to the film laminate structure 97,which directs light 101 to a surgical area 102 to be illuminated.Adhesive may be provided along light input cable 98 and/or film laminatestructure 97 for attaching the illuminator film assembly to retractor99.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventions. Otherembodiments and configurations may be devised without departing from thespirit of the inventions and the scope of the appended claims.

We claim:
 1. A medical illuminator comprising: a surgical retractorhaving a blade; a waveguide secured to the retractor blade, thewaveguide conveying light through total internal reflection; a lightconduit conveying light from a light source to the waveguide; and one ormore pre-cut optical film pieces removably secured to the waveguide forextracting light from the waveguide through the pre-cut optical film anddirecting the extracted light to a surgical field, wherein the pre-cutoptical film pieces have an area smaller than the surface area of thewaveguide.
 2. The medical illuminator of claim 1 wherein the one or morepre-cut optical film pieces further comprise: an optical film layerhaving a light directing portion and a tab portion; the orientation ofthe tab portion relative to the light directing portion indicating thedirection of extracted light from the light directing portion; and anadhesive layer applied to the light directing portion for removablysecuring the light directing portion to the waveguide, the adhesivelayer performing some index matching between the waveguide and theoptical film layer.
 3. The medical illuminator of claim 2 wherein thetab portion is color coded to indicate the degree of focus ordirectionality of the extracted light.
 4. The medical illuminator ofclaim 1 wherein the one or more pre-cut optical film pieces furthercomprise: an optical film layer having at least one diffuse lightdirecting portion and at least one focused light directing portion; andan adhesive layer applied to the light directing portions for removablysecuring the light directing portions to the waveguide, the adhesivelayer performing some index matching between the waveguide and theoptical film layer.
 5. The medical illuminator of claim 2 furthercomprising: at least one pre-cut optical film pieces removably securedto the waveguide for extracting diffuse light from the waveguide throughthe pre-cut optical film and providing the extracted light in the areaof a surgical field; at least one pre-cut optical film pieces removablysecured to the waveguide for extracting focused light from the waveguidethrough the pre-cut optical film and directing the focused light to aselected portion of a surgical field.